ML20216H783
| ML20216H783 | |
| Person / Time | |
|---|---|
| Site: | Calvert Cliffs  |
| Issue date: | 09/28/1999 |
| From: | Cruse C BALTIMORE GAS & ELECTRIC CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| NUDOCS 9910040031 | |
| Download: ML20216H783 (10) | |
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Charle) H. Cruse Calvert Cliffs Nuclear Power Plant i Vice Pr:sident 1650 Calvert Cliffs Parkway Nuclear Energy
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Lusby, Maryland 20657 J
410 495-4455 l A Member of the Constellation Energy Group 1 l
September 28,1999 I
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U. S. Nuclear Regulatory Commission ,
Washington, DC 20555 l ATTENTION: Document Control Desk
SUBJECT:
Calvert Cliffs Nuclear Power Plant Unit Nos.1 & 2; Docket Nos. 50-317 & 50-318 l Additional Information Regarding the License Renewal Application for Calvert l Cliffs Nuclear Power Plant. Units 1 and 2 l l
REFERENCES:
(a) Letter from Mr. D. B. Matthews (NRC) to Mr. C. H. Cruse (BGE), dated March 21,1999, "Calvert Cliffs Nuclear Power Plant, Units 1 and 2, License Renewal Safety Evaluation Report" (b) Letter from Mr. C. H. Cruse (PGE) to NRC Document Control Desk, dated July 2,1999, " Response to License Renewal Safety Evaluation Report" (c) Letter from Mr. C. H. Cruse (BGE) to NRC Document Control Desk, dated July 16,1999, " Response to License Renewal Safety Evaluation Report - Review Comments" (d) Letter from Mr. D. L. Solorio (NRC) to Mr. C. H. Cruse (BGE), dated i August 12,1999, " Status of Open and Confirmatory Items from March 21, 1999, Safety Evaluation Report for Baltimore Gas and Electric Company's License Renewal Application for Ca! vert Cliffs Unit Nos. I and 2" Reference (a) forwarded the Safety Evaluation Report (SER) for Baltimore Gas and Electric Company's (BGE's) application for the renewal of the operating licenses for Calvert Cliffs Nuclear Power Plant Units 1 and 2, and included certain open end confirmatory items. References (b) and (c) were BGE's responses to the open and confirmatory items and general review comments. Reference (d) provided a short list of items for which the NRC requested interaction with BGE to seek additional information, clarifications, and to propose an acceptable way to resolve these items. Some of those interactions have h ,
occurred and, while other interactions continue, this letter is being sent to provide timely information useful to the NRC staffin finalizing the SER.
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9910040031 990928 NRC Distribution Code A036D PDR ADOCK 05000317 p PDR-
, Document Control Desk
- . . September 28,1999
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i During these interactions, the need for certain other additional information and clarifications was reali7ed.
All of this additional inforn'ation is provided in Attachment (1).
, ' Should you have questions regarding this matter, we will be pleased to discuss them with you.
Very truly yours, l
At #
STATE OF MARYLAND :
- TO WIT:
COUNTY OF CALVERT ' :
I, Charles H. Cruse, being duly sworn, state that I am Vice President, Nuclear Energy Division, Baltimore l Gas and Electric Company (BGE), and that I am duly author: zed to execute and file this response on E behalf of BGE. To the best of my knowledge and belief, the statements contained in this document are f . true and correct. To the extent that these statements are not based on my personal knowledge, they are 1
) ' based upon information provided by other BGE employees and/or consultants. Such information has been reviewed in accordance with company practice and I believe it to be reliable.
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/s . Zs,es -
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Sub ri ed and sworn before,p
,thisf a ay Notary)Public in and for the State of Maryland and County of of f 2/f4rtl/A2999.
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WITNESS my Hand and Notarial Seal: ,fA > . RLL Notary Public
' My Commission Expires: b I MA l ,
' Date 1
, CHC/DLS/ dim 1
Attachment (1): Additional Information Regarding the License Renewal Application for Calvert Cliffs Nuclear Power Plant, Units 1 and 2 cc: R. S. Fleishman, Esquire C. L Grimes, NRC J. E. Silberg, Esquire D. L.' Solorio, NRC l- S. S. Bajwa, NRC . .
Resident inspector,NRC i A. W. Dromerick, NRC . R. I. McLean, DNR L H. J. Miller, NRC J. H. Walter, PSC p
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., , ATTACHMENT (1)
ADDITIONAL INFORMATION REGARDING TIIE LICENSE RENEWAL APPLICATION FOR CALVERT CLIFFS NUCLEAR POWER PLANT, UNITS 1 & 2 l
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Baltimore Gas and Electric Company Calvert Cliffs Nuclear Power Plant September 28,1999
ATTACIIMENT (1)
ADDITIONAL INFORMATION REGARDING TIIE LICENSE RENEWAL APPLICATION FOR CALVERT CLIFFS NUCLEAR POWER PLANT, UNITS 1 AND 2 It m #1 - Regarding Safety Evaluation Report (SER) Open Items 3.10.3.2.1-1 and 4.1.3 2:
As stated in Reference (1), "the staff understands that Baltimore Gas and Electric Company [BGE]
intends to manage the tendon prestress force TLAA [ time-limited aging analysis] as an aging I management program under 10 CFR 54.21(c)(1)(iii)." NRC requested information in four areas, which is provided below.
- 1. The parameters monitored or inspected per 10 CFR 50.55a(b)(2)(ix)(b).
There is a discussion of BGE's current surveillance program in Updated Final Safety Analysis
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Report (UFSAR) Section 15.6 (part of the " Technical Requirements Manual"). Key areas are as )
follows:
- Normalized tendon liftoff forces; e Wire sample; and
. Visual inspections.
Although paragraph 10 CFR 50.55a(b)(2)(ix)(B) is limited to evaluation of prestressing forces in consecutive surveillances, we plan to inspect all of the parameters listed in (ix).
- 2. The acceptance criteria such that projected tendon force trending remains above the predicted lower limit.
The 1998 Edition of American Society of Mechanical Engineers (ASME) Code Section XI, IWL-3221 gives the requirements for acceptance by examination, including the provision that "the l prestressing forces for each type of tenden . . . and the measurement from the previous j examination indicate a prestress loss such that predicted tendon forces mect the minimum design i prestress forces at the next scheduled examination." If we would not meet this criterion, the i options are acceptance by evaluation (IWL-3222) and acceptance by repair / replacement activity I (IWL-3223).
- 3. Corrective actions that include systematic retensioning of tendon population to ensure the adequacy of prestressing force.
Potential actions include:
e " Bootstrapping," or increasing the tension in all or part of the tendons; e Replacing selected tendons with new tendons; and e Reanalysis.
.4. Operating experience as applicable to tendon force monitoring.
Other plants have observed prestressing wire corrosion, end anchorage failures, water in the vertical tendons, and greater than expected relaxation due to solar heating.
Baltimore Gas and Electric Company found broken wires in the 1997 inspection, and submitted reports to the NRC dated August 28,1997, October 28,1997, and May 14,1998. At that time, we thought it prudent to replace a nuntber of tendons.
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ATTACHMENT (1)
ADDITIONAL INFORMATION REGARDING TIIE LICENSE RENEWAL APPLICATION FOR CALVERT CLIFFS NUCLEAR POWER PIANT, UNITS 1 AND 2 Since 1997, we researched tendon sheathing material (" grease"), ran tests on grease replacement methods, and wrote a specification for and received bids for tendon replacement. We also contracted a specialty consulting firm for additional analyses to verify and/or refine the UFSAR values for containment strength.
In addition, we performed visual inspections on nearly half of the vertical tendons in 1999, including all previously categorized as having " severe corrosion." We found a few more broken wires. Since this is a low number, we have another specialty consulting firm reevaluating the wire break projections for future years, We are reevaluating our position, and expect to submit additional information to the NRC later this year.
In conclusion, BGE feels this adequately aesses the issues and demonstrates BGE's ability to effectively manage this TLAA.
Item #2 - Regarding SER Confirmatory Item 3.1.5.3-1 l Baltimore Gas and Electric Company will include, in the UrSAR and/or in our Quality Assurance l
Program description, an explicit commitment that those BGE Appendix B Quality Assurance Program elements specifically related to corrective actions, confirmation processes, and administrative controls, apply to non-safety-related systtms, structures, and components that are subject to aging management review (AMR) for license renewal.
Item #3 - Regarding SER Open Item 2.2.3.8-1 Baltimore Gas and Electric Company agrees to consider certain components of the station blackout diesel generator building within scope far license renewal and subject to AMR. Baltimore Gas and Electric Company is performing that AMR and will provide the results to NRC as soon as they are known.
Item #4 - Regarding SER Open Item 2.2.3.23.2.1-1 From the Statements of Consideration for 10 CFR Part 54, ". . . the Commission agrees that for purposes -
of 54.4, the scope of 50.49 equipment to be included within 54.4 is that equipment already identified by licensees under 50.49(b). Licensees may rely upon their listing of 10 CFR 50.49 equipment, as required i by 10 CFR 50.49(d), for purposes of satisfying 54.4 with respect to equipment within the scope of 50.49." l As discussed in Reference (2) (BGE Response to NRC Request No. 4a), the establishment of expected normal plant operating ambient temperatures should be representative of that which is expected to be seen by the component during its installed life. The cavity cooling system, including the ductwork, provides the normally expected ambient temperature for this area.
The equipment that provides the normally expected environment is not specifically required to be identified as 10 CFR 50.49. The cavity cooling ductwork is in this category. Failure of cavity cooling will not prevent the execution of the critical safety functions identified in 10 CFR 50.49(b)(1) during and following a design basis accident. During or following a design basis accident, the cavity cooling function is assumed to be unavailable.
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ATTACIIMENT (1) !
l ADDITIONAL INFORMATION REGARDING TiiE LICENSE RENEWAL APPLICATION FOR CALVERT CLIFFS NUCLEAR POWER PLANT, UNITS 1 AND 2 i
Furthermo e, per Reference (3), the cascading failure effects characterized by 10 CFR 54.4(a)(2) need not be applied to 10 CFR 54.4(a)(3) scoped items.
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Please note that it does not follow that failure of the cavity coedng system, or any ofits components, can i occur without an evaluation of the impact. This situation would be treated as a degraded condition and l
entered into our corrective actiori process. Operability of affected systems, structures, and components !
would be evaluated, including affects on 10 CFR 50,49(b) equipment. Continued plant operation would be determined based on the operability evaluation conclusions, until such time (commensurate with the safety significance of the issue) that corrective actions can be taken to correct the degraded condition.
l Item #5 - Regarding SER Open Item 2.2.3.33.2.2-1 This SER open item sought clarification on the cross referencing with the License Renewal Application l (LRA) to Section 6.2, Electrical Commodities. The following additional clarification is provided.
The following LRA sections referenced Section 6.2, but should not have:
4.1," Reactor Coolant System;"
53," Component Cooling System;" and 5.12, " Main Steam, Steam Generator Blowdown, Extraction acam, and Nitrogen and Hydrogen Systems."
The following LRA sections should have referenced Section 6.2, but did noc 5.14," Radiation Monitoring System;"
5.15," Safety Injection System;" and 5.16," Saltwater System."
Item #6 - Regarding SER Open Item 3.2.3.1.2-1 This SER open item contained four bullets, which BGE responded to in Reference (4). The following is a clarification of our response to the first bullet:
The Calvert Cliffs Nuclear Power Plant (CCNPP) Fatigue Monitoring Program (FMP) was initially created as part of a Combustion Engineering Owners Group project to establish a program to monitor, evaluate and record thermal fatigue usage in me components required for safe operation and shutdown.
Additional objectives were to provide a regulatory basis for component life assurance and life extension, and a technical basis for the plant Technical Specifications associated with fatigue. As outlined in our July 2,1999 response to 013.2.3.1.2-1, Combustion Engineering (CE) performed a review of the
" Critical Systems" in the plant to identify those components with controlling fatigue usage limits. Also listed in our response to the open item were systems or components, which were outside CE's scope of work and specifically excluded from the review. Two items that were not identified by CE as being outside the initial FMP scope were the power-operated relief valve block valves and thecontrol element drive mechanism housings. The following is a list of items that were excluded from the initial CE project:
- Nuclear Steam Supply System Sampling System; e pressurizer safety valves; 3
ATTACHMENT (1)
ADDITIONAL INFORMATION REGARDING Tile LICENSE RENEWAL APPLICATION FOR CALVERT CLIF NUCLEAR POWER PLANT, UNITS 1 AND 2 e power-operated relief valves; e auxiliary feedwater isolation and check valves; e main feedwater isolation and check valves; e reactor coolant pumps (RCPs);
e power-operated relief ,alve block valves; and e control element drive mechanism housings.
While these items were excluded from the CE scope of review, this is not meant to imply that these items were not designed with the appropriate " fatigue" design basis. In fact, to the extent required by the construction code, each of these items has a Stress Report or Design Report.
Additionally, CE did not include the effects of loadings such as thermal stratification or stripping (e.g., NRC Bulletins 88-08 and 88-11). At the end of the CE project, the large majority of the " fatigue critical" items had been identified. However, the review was not comprehensive for all of CCNPP.
$[ Subsequent to the comp!etion of the CE project, BUE adopted the use of Elec Institute's FatiguePromsoftware to implement the FMP. With the progression of the BGE's license renewal efforts, BGE determined that the FMP could be modified to be a comprehensive program (i.e., include the portions of CCNPP and phenomena excluded by CE), and would serve as an effective program to manage aging due to fetigue. As such, BGE has performed a great deal of the screening or
" evaluations" that are analogous to that performed by CE in the initial program scope. However, not all items have been reviewed or incorpc, rated into the FMP at this date. As a result, BGE identified several items that needed to be evaluated and potentially included in the FMP as part of the license renewal application This list of items to be evaluated is very similar to the list of items that were outside the scope of the CE review; however, the two lists are not identical. The differences result from two factors:
- 1. The items have been reviewed and found not to be " fatigue critical" in the context of the FMP. )
- 2. BGE's comprehensive expansion of the FMP screening population has identified other items that need to be evaluated for potential inclusion in the FMP.
The bact: ground provided herein and in the BGE response to this open item in July 1999 should clarify the differences in the list of items identified by BGE that require review for inclusion into the FMP and l the list ofitems that were excluded from the scope of the ABB-CE review.
Item #7 - Regarding BGE comment on SER page 3-69 In Reference (5), BGE provided a comment on SER page 3-69 that relates to experience with fatigue of RCP shaft seal controlled bleed-offlines.' Additional information in this area is provided below.
As described in CCNPP Licensee Event Peport (LER) 85-0134)0, while operating in Mode 1 on October 9,1985, routine performance of Calvert Cliffs Procedure STP-O-027-1, " Reactor Coolant System Leak Evaluation," indicated an increasing trend in the Reactor Coolant System leak rate for the j
previous 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />. The source of the Reactor Coolant System leakage was determined to be a cracked I weld at the attachment point between No. I1 A RCP shaft seal and the controlled bleed-off(CBO) line. )
Similar failures have occurred on both Unit I and Unit 2 RCP shaft seal CBO lines (Unit 1 - LERs 80-24 and 83-20, and Unit 2 - LER 84-06). The cause of the weld failure was determined to be high tension and I torsional stresses with high cycle fatigue failure. Excessive stresses were caused by the vibratory motion l
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ATTACHMENT (1)
ADDITIONAL INFORMATION REGARDING TIIE LICENSE RENEWAL APPLICATION FOR CALVERT CLIFFS NUCLEa POWER PLANT, UNITS I AND 2 6 . ;
of a relatively massive, unsupported CBO line flange located several inches from the RCP shaft seal cartridge.
Immediate corrective action was to remove the existing CBO lines and their associated flange connections from all Ur,it 1 RCPs aad replace them with a continuous section of piping between the RCP shaft seal and the undamaged piping downstream of the original flanged connection.
Long-term corrective actions are: =
- 1. A modification was implemented during planned outages that either relocated the flange ;
connection to minimize stress and vibrational-induced fatigue failures of the CBO line, or i
replaced the CBO line with a continuous run of piping, eliminating the flange connection.
- 2. Non-destructive examinations of each RCP seal attachment weld are performed during each cold shutdown and seal rebuild. !
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Also, vibration monitoring of the RCPs during optration is continuing.
- 4. The importance of handling and rigging of RCP seals to minimize stress on RCP attachment welds is emphasized to maintenance personnel, i
The mitigative corrective actions taken, combined with continuing monitoring, will prevent future vibratory fatigue-related failures of the CBO lines. l Item #8 - Regarding Void Swelling Baltimore Gas and Electric Company does not consider void swelling as plausible. However, if it does I occur, gross deformation will be detected by VT-3 (a type of visual examination described in ASME XI, IWA-2213) inspections already required by ASME Section XI. Baltimore Gas and Electric Company is following this issue closely through our participation in Electric Power Research Institute's Materials Reliability Program Reactor Vessel Internals Issues Task Group.
Item #9 - Regarding a previous change to LRA Section 5.9 (Feedwater System)
Reference (6) provided Integrated Plant Assessment (IPA) results changes and errata to the BGE LRA.
Section 5.9,_"Feedwater System," of Reference (6) included an IPA results change that added three device types in the area discussing scoping, and subsequently dispositioned the three as active device i types. One of the three, " Panel," is not active. Therefore, the following changes should be made to Section 5.9 of the LRA:
In Section "5.9.1.3, " Components Subject to Aging Management Review," in the first bullet under
" Device Types Subject to Aging Management Review," " Sixteen" (formerly " Thirteen") should be changed to " Fifteen," and " Panel" should not be included in that bullet. A third bullet should be added, as follows:
- "One device type in this system, Panel, was evaluated in Section 6.2, " Electrical Commodities."
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. 1 ATTACHMENT (1) ;
ADDITIONAL INFORMATION REGARDING TIIE LICENSE RENEWAL APPLICATION FOR CALVERT CLIFFS NUCLEAR POWER PLANT, UNITS 1 AND 2 1 i
Item #10 - Regarding NRC Request for Additional Information 3.1.1 Regarding BGE's response to NRC Request for Additional Information 3.1.1 (Reference 7), BGE provides the following clarification: l J
System 68, " Spent Fuel Storage," was not listed in Table 3.1-1 of the LRA because there are no component supports in that system.
Item #11 - Regarding Sections 3.1 and 5.18 of BGE's July 2,1999 Response !
Reference (4) responded to the SER open and confirmatory items and also included changes to the BGE LRA, as Attachment (3). Section 3.1, " Component Supports," and Section 5.18, " Spent Fuel Pool Cooling System," both discuss Preventive Maintenance (PM) Repetitive Task 10672001 and our intention to modify and use this task for managing the aging of the supporting components of the spent fuel pool filter and demineralizer vessel / strainer and local piping.
In Section 3.1, this repetitive task is described as implementing Calvert Cliffs Procedure GEN-05,
" Radioactive Filter Replacement." This is not the intended plan. Therefore, please delete the following words in the first full paragraph on page 2 of Attachment (3) of Reference (4), which starts with ,
"Specifically, PM repetitive task . . :" l "will implement GEN-05, which" Delete the next to the last sentence in the paragraph on page 1 that starts with, "1. SFP Cooling Supports i in a High Radiation Area." The sentence is, "This repetitive task will . . . GEN-05 (Reference 2), which I will be modified."
Delete "CCNPP Technical Procedure, GEN-05," in the row item listed under the second bullet on page 3 of Attachment (3) of Reference (4). Also delete Reference (45) for GEN-05 under the third bullet on page 3 of Reference (4).
Item #12 - Regarding HGE Comment on SER page 3-135 In Reference (5), BGE provided a comment on SER page 3-135, last bullet, that requested NRC to add j
PM Checklist MPM09005 to a list on that page. Baltimore Gas and Electric Company had not informed j' NRC of this IPA change previously. We apologize for the comment. Accordingly, we wish to report that we have made a change to the aging management approach in this area, as follows:
i The PM checklist for the Primary Containment Heating and Ventilation System Gravity Dampers, MPM0411, which is credited for aging management in BGE LRA Section 5.llB, applies only to Unit 1. To apply the same aging management program to the Unit 2 Gravity Dampers, BGE will now credit PM Checklist MPM09005. This checklist will be credited with discovering the effects of radiation damage, elastomer degradation, and wear of the damper seals.
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, , ATTACHMENT (1)
ADDITIONAL INFORMATION REGA!tDING Tile LICENSE RENEWAL APPLICATION FOR CALVERT CLIFFS NUCLEAR POWER PLANT, UNITS 1 AND 2
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- REFERENCES.
- 1. Letter from Mr. D. L. Solorio (NRC) to Mr. C. H. Cruse (BGE), dated August 12,1999, " Status of Open and Confirmatory Items from March 21,1999, Safety Evaluation Report for Baltimore Gas and Electric Company's License Renewal Application for Calvert Cliffs Units Nos. I and 2"
- 2. Letter from Mr. C. H. Cruse (BGE) to NRC Document Control Desk, dated 2/19/99; " Response !
to Request for Specific Information Needed for the Staff Evaluation of Environmental Qualification for License Renewal" '
- 3. Letter from Mr. C.1. Grimes (NRC) to Mr. D. J. Walters (NEI), dated August 5,1999, " License Renewal Issue No. 98-0082, Scoping Guidance"
- 4. Letter from Mr. C.11. Cruse (BGE) to NRC Document Control Desk, dated July 2,1999,
" Response to License Renewal Safety Evaluation Report"
- 5. Letter from Mr. C. H. Cruse (BGE) to NRC Document Control Desk, dated July 16, 1999,
" Response to License Renewal Safety Evaluation Report - Review Comments"
- 6. Letter from Mr. C. H. Cruse (BGE) to NRC Document Control Desk, dated February 4,1999,
" Changes to the Application for License Renewal"
- 7. Letter from Mr. C. H. Cruse (BGE) to NRC Document Control Desk, dated November 19,1998,
" Response to Request for Additional Information for the Review of the Calvert Cliffs Nuclear Power Plant, Units 1 & 2, Integrated Plant Assessment Reports for Component supports and ,
Piping Segments that Provide Structural Support, and Errata" l 7
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